Wells was 9 of 13 from the field and 10 of 10 from the free throw line to lead the seventh-seeded Terrapins (22-11).

They never trailed, held the league's best team from 3-point range to 4-of-25 shooting from beyond the arc, and bolstered their NCAA tournament credentials with their second straight win over Duke.

Mason Plumlee had 19 points to lead second-seeded Duke (27-5), which had the ball trailing by six points with about 2 minutes left after Seth Curry hit a rare 3-pointer and the Blue Devils got an even rarer defensive stop.

But Tyler Thornton missed 3-pointers on consecutive trips downcourt and Wells and Seth Allen each hit two free throws, with Allen's stretching the lead to 77-67 with 1:44 left.

Diplomats and negotiators kept working Tuesday as a deadline approached to reach a deal on a framework agreement on Iran's nuclear program, but a U.S. State Department official said the discussion may continue after the cutoff.